Income taxes (Details) $ in Thousands	Sep. 30, 2020 USD ($)
Income Tax Disclosure [Abstract]
Unrecognized tax benefits	$ 91,592
Unrecognized tax benefits that would impact effective tax rate if recognized	91,592
Accrued interest related to the gross unrecognized tax benefits excluded from the unrecognized tax benefits	14,721
Decrease in unrecognized tax benefits that is reasonably possible (up to)	$ 30,000